Biopsies are performed on human patients in order to determine the nature of a suspicious growth, tumor or mass found on or inside the body. The growth can be initially identified by several methods, including visual examination, palpitation, x-ray, MRI, ultrasound imaging, or other detection means. Once identified, there is a pressing need to rapidly evaluate the tumor as to whether it is malignant (cancerous) or benign. A sample of suspect tissue is removed by biopsy, and then evaluated, generally under a microscope. If cancer is detected and treated in the early stages of growth, there is a significant increase in the survival rate of the patient.
While the need for an accurate biopsy sample of sufficient size to make a correct diagnosis is clear, scarring and disfigurement are also concerns, particularly when dealing with women's breast cancer. Recently, development efforts have focused on biopsy methods, which are less invasive than the current standard of care, the open excisional biopsy. Percutaneous methods for performing biopsies include fine needle aspiration (FNA) and core biopsies. Core biopsies are generally more accurate than FNA because they remove an intact sample of cells, simplifying diagnosis and post-biopsy relocation of suspected growths.
The original core biopsy devices consisted of a coring needle, i.e. a hollow tube with a sharpened edge, to obtain a plug of tissue. Such a device was inserted into the suspect region and withdrawn. Once the coring device was removed from the body, the plug of tissue was pushed out of the coring needle.
Although these coring needle devices provided a tissue core, they also removed a large section of healthy tissue in the process. They were also slow to use, and multiple puncture wounds were created in the breast when more than one sample was taken.
In response to the above deficiencies, an improved method of taking multiple biopsy samples was developed. The TRUE CUT.RTM. needle (sold by Travenol Laboratories, Deerfield, Ill.) provides the following advantages over the original core biopsy device or the use of hollow needles: 1) the TRUE CUT.RTM. device has a pointed stylus that enables the device to penetrate the body to the surgical site without removing a core of healthy tissue; 2) the device uses an exterior sliding cutter tube that covers or shields the biopsy or tissue sample within the device as it is being withdrawn. To obtain a tissue sample, the TRUE CUT.RTM. needle depends on the passive prolapse of tissue into a tissue receiving notch within the stylus. Once the tissue is prolapsed into the notch, the cutting tube is advanced to sever the tissue sample.
The above device was revolutionary in the field at the time because it removed tissue samples from the desired surgical site without affecting surrounding healthy tissue, and the instrument removed the sample from the body intact. However, the device still required multiple insertions and removals from the surgical site and subjected the tissue at the point of insertion to repeated tissue trauma. Additionally, its use was time consuming as the instrument required disassembly to remove each tissue sample. Moreover, the size and shape of the tissue samples tended to be inconsistent. This may have been caused by the need for the operator to wait for the tissue to passively prolapse into the device and by the forced migration of the tissue away from the cutter as it advanced.
In response to the need for a method to acquire consistent tissue samples, vacuum was added to biopsy instruments. The application of vacuum to the tissue receiving chamber of the biopsy instrument drew the tissue into the chamber. This type of device offered consistent tissue sample size and held the tissue in place as the knife was advanced to sever the tissue. U.S. Pat. No. 3,590,808 to Wulf Muller discloses such a device.
Whereas the Muller device did address the need for vacuum to effectively hold the tissue in place to provide consistent samples, it did require an insertion and removal of the device from the body for each tissue sample and accompanying tissue trauma.
Recognizing the shortcomings of the previous devices, an improved surgical biopsy device was developed and disclosed in U.S. Pat. No. 5,526,822 to Burbank et al. The device is embodied in the MAMMATOME.RTM. biopsy device. (manufactured and sold by Ethicon Endo-Surgery, Inc., Cincinnati, Ohio) It is an automated surgical biopsy device that is inserted into a surgical site and multiple tissue samples are removed from the instrument without withdrawing the instrument from the body. Additionally, vacuum is used to draw tissue into the instrument and to hold the tissue while it is cut. This provides the pathologist with elongated, intact tissue samples. This device includes an outer piercing needle with a single aperture port. A hollow tubular cutter having a single cutting edge is slidably and rotatably mounted within the outer piercing needle and cuts tissue drawn into the single aperture port. The cut tissue sample is captured within the hollow of the tubular cutter and is withdrawn from the surgical site within the tubular cutter. The tissue sample is then ejected from the tubular cutter into a biopsy cage or cartridge that holds multiple tissue samples for storage.
It is important to note that presently, the MAMMATOME.RTM. device utilizes a biopsy cage or cartridge that stores multiple tissue samples. Placement of the samples into the cage can be time consuming and care must be taken to place the samples in some sequence of order to ensure proper analysis by pathology.
One type of known sample handling mechanism and technique is disclosed in U.S. Pat. No. 5,524,634 (Turkel et al.). However, Turkel et al. only teaches a particular container and method of storing and labeling tissue samples.
Presently, there is no known surgical biopsy device and its method of use that can meet all of the needs outlined above in addition to providing an efficient mechanism for protection and identification of multiple biopsy samples.